Rock drill front end



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.10H/v c. caf? T/s INVENTOR yEn! ATTORNEY Patented Mar. 30, 1937 UNITED STATES PATENT OFFICE ROCK DRILL FRONT END John C. Curtis, Gariield Heights, Ohio, assignor to The Cleveland Rock Drill Company, Cleveland, Ohio, a corporation of Ohio Application September 6, 1935, Serial No. 39,465

7 Claims.

Other objects more or less ancillary to the foregoing reside in the specic construction and aggroupment of the elements peculiar to this structure, as will become apparent from a more complete examination of this specification.

Referring to the drawing which illustrates the invention:

Fig. l is an elevational view partly in section of a rock drill iront end having the invention applied thereto.

Fig. 2 is a cross sectional view taken through a plane indicated by line 2 2 of Fig. 1.

Fig. 3 is a View similar to Fig. 2 but taken through a plane indicated by line 3 3 of Fig. 1.

Fig. 4 is also a cross sectional View taken through a plane indicated by line 4 4 in Fig. 1.

Fig. 5 is an end view of the rock drill front end illustrating the retainer in the position shown in Fig. 1.

In this illustrative construction, I 8 represents a rock drill front housing having its upper end thereof guided within a mounted within the bushing II.

Leading from the front end of the housing IIJ into the interior thereof, there is an aperture formed of three fiat bottom bores I5, IB, and I1. The bore I6 is disposed in coaxial alignment with the longitudinal center axis of the housing, while the bores I5 and I1 are located on the side thereof in parallel alignment therewith to form an aperture of elongated cross section. Toward its end, the bore I6 is circularly enlarged as at I8 to afford the communication of the bores I5 and I1 with the front end oi the hammer piston I3. Each bore I5 and I1 has an elongated element or guide I9 mounted therein, with one end engaging the flat bottom of the bore, while the other end thereof is substantially ush with the front end The inner wall of the guides I9 is arcuated as at 29, and provided with a U-shaped slot 2i extending the full length thereof. The

housing I is secured to the rock drill cylinder I2 by a pair of bolts 23 extending therethrough to receive cooperating nuts 24. The plate 22 is provided with a protuberance or key 25 extending upwardly therefrom between the guides I9, which have their front end machined as at 26 to snugly receive the same, thus positioning the U-shaped to the housing I0. The plate 22 is formed with a bore 21 disposed in coaxial alignment with the bore I 6, and U-shaped slots 28 extending away from the bore 21 in coaxial alignment with the slot 2| of the guides I9.

Adjacent each bolt 23, the plate 22 is provided with a transversally apertured boss 29 having a bolt 39 ceive a pair of links 3|. One pair of links has pivotally secured thereto by a bolt 32 a fork shaped member 33 having each side arm thereof provided with a hook 34. Similarly secured to member 33. there is a bore 38 corresponding to the bore 21 of the plate 22 and located in coaxial alignment therewith. vided with U-shaped slots 39 extending therefrom into the members 33 and 35 in diametrical opposition to each other. `The upper portion of the plate 22, while the lower portion thereof is inclined as at 4 I.

Slidably mounted within the slot of the guides I9, there is the shank 42 of a tool implement. This shank is of rectangular cross section with formed in the plate 22 and members 33 and 36 depending therefrom. The free end of the shank is circularly enlarged as at 43 to provide an adequate end surface adapted to receive the blows of the hammer piston I3. In practice it has been found that when the free end of the shank is not enlarged as shown in the drawing, the blows imparted thereon by the hammer piston cause the middle portion of the side walls of the shank to flare or expand outwardly. The bore I6 provided between the guides I9, together with the arcuated inner wall 20 of the latter, afford suicient clearance for a free passage of the enlargement 43, which may be purposely provided at the end ofthe shank, orrmay be the result of th blows imparted thereto by the hammer piston. The plate 22 being provided with a bore similar to the bore IE, will also permit the free passage of the end of the shank irrespective of the enlargement formed therein.

Referring to the mechanism depending from the plate 22, it will be understood that upon downward pressure exerted on the member 33, the upper edge of the end walls of the slots 39 will be moved inwardly in clamping engagement with the shank, thus retaining the latter within the housing I0. The enlargement 43 formed at the end of the shank is free to pass through the bore 38 in the tool retaining device, thus permitting the shank to be introduced into or removed from the housing l0 without disconnecting the members 33 and 38.

Although the foregoing description is necessarily of a detailed character, in order to completely set forth the invention, it is to be understcod that the speciiic terminology is not intended to be restrictive or confining and it is to be further understood that various rearrangements of parts and modification of structural detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

I claim:

1. In a front end construction for rock drills, a front housing formed with an aperture, a tool implement having a shank slidably guided within said aperture, said shank and aperture being of rectangular cross section with the side walls thereof longer than its end walls, the middle portion of the side walls of said shank toward the free end thereof being flared to form an enlarged end surface, and a passage between the marginal edge of the side walls of said aperture affording the free introduction or removal of said shank into or from said aperture irrespective of the flared portion of said sha 2. In a front end construction for rock drills, a front housing, guideways within said housing, a tool implement having a shank of rectangular cross section slidably guided within said guideways, and an enlargement at the free end of said shank, said guideways formed and disposed in a manner affording the free slidable movement of said shank therein irrespective of said enlargement.

3. In a front end construction for rock drills, a front housing, guideways within said housing, a tool implement having a shank slidably guided within said guideways, an enlargement formed on said shank extending to the free end thereof to cause the free end area of said shank to be greater than the normal cross sectional area thereof, and a clearance between said guideways affording the free slidable movement of said shank irrespective of said enlargement.

4. In a front end construction for rock drills, the combination with a front housing having an aperture formed therein, of a tool implement having a shank slidably guided within said aperture, an enlargement formed at the free end of said shank, a tool implement retaining device carried by said housing movable in'operative or inoperative position for preventing or permitting the removal of said shank from said housing, and a passage within said device arranged and disposed in a manner whereby the enlargement formed at the end of said shank remains in spaced relation with said device irrespective of the position of the later.

5. In a front end construction for rock drills, a front housing having a duality of bores leading from its front en-d into the interior thereof, said bores being diametrically opposed to each other in parallel alignment with the longitudinal center axis of said housing, an element within each of said bores having a guideway formed therein, a tool implement having a shank slidably guided within the guideway of said elements, and means for detachably securing said elements in said housing against movement relative thereto.

6. In a front end construction for rock drills, a front housing, an opening leading from the front end into the interior of said housing in coaxial alignment with the longitudinal center axis thereof, a duality of elements within said opening, the inner wall of said opening and the external wall of said element being formed for cooperative engagement in a manner whereby said elements are maintained in parallel spaced relation with each other, a guideway formed within each of said elements in opposition to each other, a tool implement having a shank slidably guided Within said guideways, and means for detachably securing said elements in said housing against movement relative thereto.

'7. In a front end construction for rock drills, a front housing having a duality of bores leading from its front end into the interior thereof, a re-i movable guideway within each of said bores, a tool implement slidably guided Within said guideways, and means for detachably locking said gui-deways in said housing against movement relative thereto.

JOHN C. CURTIS. 

